Millions of dollars in termination fees would have to be paid by either party if the mega-merger between Progress Energy and Duke Energy becomes unhinged, according to new regulatory documents.

Raleigh-based Progress (NYSE:PGN) would be obligated to pay $400 million to Duke if Progress officials step away from the transaction, while Duke (NYSE:DUK) would be liable for $675 million if that company canceled.

The numbers were included in new U.S. Securities & Exchange Commission filing on the proposed deal.

Moreover, both parties would pay up to $30 million in fees and expenses to the other, if their actions prompt a cancellation.

In other fine print:

â¿¢ Progress has agreed not to increase its regular shareholder dividend pending completion of the deal; Duke, on the other hand, reserved the right to adjust its regular dividend upward.

â¿¢ The transaction, under which Progress shareholders would receive 2.6125 Duke shares for each of their Progress shares, is predicated on Duke issuing additional common stock and conducting a reverse stock split.

â¿¢ Among the regulatory agencies that have to approve the deal are the Federal Energy Regulatory Commission, the Nuclear Regulatory Commission, the Federal Communications Commission and various state public service and utility commissions.